Design of an anti-offset magnetic coupler for wireless charging of underwater vehicles

The limitations of autonomous underwater vehicles (AUVs) in military, civil, and scientific research are due to their current energy supply and charging issues. Wireless power transfer technology, which avoids direct electrical connection, and the non-contact energy transfer method, can improve the safety and convenience of underwater charging. This, in turn, can effectively enhance the range and operating radius of AUVs. This paper proposes a simple and reliable magnetic coupling structure that is resistant to offset for underwater wireless charging scenarios. Finite element simulations are conducted to compare the electrical parameters and anti-offset performance in air and seawater media. Using mutual inductance M as the evaluation index, the structure can be realized as a circular anti-offset region with the central point as the center and a radius of 90% τ, where τ is the radius of the receiving coil, in different media. The introduction of seawater did not cause additional fluctuations in the electrical parameters of the coupled structure, but it did increase eddy current losses, reducing efficiency by 4%, which is within acceptable limits.